Currently, backlight modules for liquid crystal displays (LCDs) mostly employ YAG phosphor LEDs to produce a source of white light, which passes through RGB color filters to produce the final output spectrum for the LCDs. Filters can only faithfully render the tones of the backlight modules. The main issue associated with current backlight modules is that the blue light is too strong, while the distributions of the green and red lights are too wide, resulting in a small color gamut. The imbalance of colors may also affect viewers' vision.
It has been proposed a technique for the LCD backlight modules that incorporate with quantum dots (QDs). Conventional LCDs generally comprise a liquid crystal panel and a backlight module. The backlight module includes a light source, a light guide plate (LGP), a reflector and other components. A quantum dot (QD) sheet is disposed above the LGP. In general, the properties of quantum dots include high fluorescent intensity, good light stability, and the ability to excite light waves of a variety of different wavelengths from a single wavelength of light.
Although the use of the QD sheet facilitates balance between the RGB colors, when applied to a liquid crystal display with a large area, the use of a large amount of quantum dots entails high costs. A method for reducing the amount of quantum dots being used is to add scattering particles in the QD sheet to compensate for efficiency; however, this would reduce the transmittance of the sheet.
Therefore, there is still a need for a solution that reduces the amount of quantum dots used while still maintaining high quantum efficiency.